Lasers & Applications: Part 1

Copyright © 2009 by Davis Multimedia, Int'l. All Rights Reserved.
As Printed in January 2009, Volume 34, No. 7 of The Engravers Journal
 
 
  Using the vector mode on a laser, you can easily cut complex patterns like this wooden puzzle from Gravograph.  

     Laser engraving systems have come a long way since they were first introduced to the industry more than 25 years ago. Today’s lasers are less expensive and easier to use, they have more power and many more features than those on the market even a few years ago. And there are more manufacturers offering more models and better service and support.
     The best thing about these systems, though, is that they are so versatile. Today’s lasers can cut or mark a wide variety of materials. That means there are literally thousands of different ways to turn your laser into a profit-making machine. This series will present a variety of different applications that laser owners may want to consider when it comes to the kinds of items they produce and/or personalize for profit.
     When the earliest laser systems came on the scene in the early 1980s, they were huge machines that weighed 1,000 pounds and were very expensive compared to their rotary engraving counterparts. That all began to change, however, as users began to find more and more applications for lasers and as suppliers began offering more products suitable for this new technology.
     Not only are today’s lasers much smaller than the early models, but they’re much faster, more efficient, easier to set up and much more versatile. In addition, there are so many different options like the red beam spot lasers, cutting grids, cylindrical attachments, air assist and self-centering capability that make the systems so user-friendly that almost anyone can operate them with little or no training.
     Instead of the constant guessing game laser users encountered each time they attempted a new job in the early days, today’s lasers come with a chart showing the settings which have been tested and proven to work for a variety of different materials. Some laser systems even have the settings built right into their drivers, allowing users to select the material from an on-screen chart rather than manually inputting the power and speed settings. This makes setups so automatic that all the user has to do is know what type of material they’re working with and where to place the item in the laser to perform the job.
     Technology advancements have also expanded the types of lasers available, giving engravers more options when it comes to choosing a laser that best suits their application. In the early days, CO2 lasers were the only option available in the R&I industry. Today, however, users can choose between CO2 lasers, YAGs and most recently the addition of fiber lasers. And if the past is any indication, the future holds the promise of even more advancements in laser technology in the areas of hardware (the laser itself), the software that drives them or the types of products and materials we can engrave with them.
     One of the problems with all of this new technology, however, is that many laser users are not taking advantage of the versatility of their systems. According to some of the laser sales representatives that I talk with, many shop owners who are purchasing lasers are only using them for a very limited number of applications. Of course, it’s certainly their choice as to how they use their lasers, but on the other hand it seems like a shame to leave such a huge gap in the potential profits they could be earning.

It’s important to clean the uncoated metal before applying the laser fusible coating. This is the CorelDRAW layout created for our sample plate. Still in the laser, you can clearly see how the thermal chemical is responding, creating a permanent black mark.

     To be sure, this is especially unfortunate considering the difficult economic times we’re facing. If you’re like most shop owners these days, you’re looking for every opportunity to enhance your bottom line. One way to do this is to maximize the versatility and productivity of every tool in the shop, especially the big ticket tools like your laser.
     When I ask some of those laser representatives why shop owners are limiting the types of products they produce with their lasers, most say the reason is that the users don’t feel comfortable trying new things and learning new skills, especially if it involves learning new computer skills.
     If you would like to increase your profits by expanding how you’re using your laser then this article series is for you. Hopefully, by providing some information on some of the different types of applications I have tried with my laser, it might help you decide if this is something you would like to try for yourself. Just remember to keep an open mind and don’t expect to try something new without making some mistakes. I can almost guarantee there isn’t a mistake you could make that I haven’t made before you, or continue to make from time to time, so roll up your sleeves and let’s try a few jobs together.
Lasering Stainless Steel & Chrome
     The first application I’d like to discuss is engraving, or should I say marking, uncoated metals. As we briefly discussed earlier, the frequency range of a CO2 laser (the wave length of the laser beam) will not have any effect on raw or uncoated metals. It will mark a few metals such as anodized aluminum (the anodized surface is heated and changes color—a process called bleaching), a special metal known as AlumaMark, available from Horizons, which is made specifically for lasers and a host of coated metals such as brass-plated steel, engraving brass or coated aluminum where it burns away the top coat (usually some kind of paint) exposing the base metal underneath.
     However, in the case of stainless steel, chromium and some other metals such as brass and aluminum, they can be marked with a CO2 laser of 15 watts or more (I prefer a 25 watt but many experts recommend a 50 watt laser) by spraying a chemical coating onto the metal prior to engraving. The chemical, when heated by the laser, actually bonds with the metal making an extremely durable, black mark. The chemical, known as a laser fusible coating, is marketed under two names, CerMark and TherMark, and is available from most laser and engraving suppliers.

The finished product shows a readable barcode, logos and other needed information on this stainless steel blank. If you opt for using paste rather than aerosol cans, an easy way to apply the paste to small items such as dog tags is to roll it on using a Q-Tip. Here are some images that show how CerMark/TherMark can be used on everyday products.

     The sample piece we will engrave here is medical grade stainless steel straight from a machine shop, which means it is likely covered with oil or other dirt and grime. The first step in this process, is to clean the metal in order to completely remove any oil, dirt or grime. To do this, I suggest cleaning the metal with mineral spirits. This will easily remove tar, oil and grime but can sometimes leave a white film. To ensure this doesn’t cause a problem, I clean the item again using isopropyl (rubbing) alcohol. Once the piece is clean and dry, the laser fusible coating can be applied.
     The chemical comes in two different forms—aerosol cans and tubs. The aerosol cans are the easiest way to apply the chemical coating but if large areas need to be covered then the tub version is much more economical. Except in a few limited applications, it is my opinion that the chemical works best if it’s sprayed on using either the aerosol cans or an air spray gun. For small jobs, a hobby-type gun does a good job but for commercial applications a paint sprayer would be more suitable. (Note: For every small item such as a pet tag that doesn’t use much chemical, try thinning a little bit of the paste and roll it on using a Q-Tip.) Some engravers prefer to brush on the chemical like paint. Whatever the method of application, two thin coats of chemical is preferred as opposed to a single heavy coat. The coating can actually be very thin but it must completely cover the area to be engraved and be allowed to dry completely.
     Once dry (about 5-10 minutes), the item can be handled and engraved using high power and low speed. The unlasered chemical is easy to scratch off so use care not to scrape it with fingernails or against other pieces of metal. A 25 watt laser at 100 percent power and 20 percent speed should produce a quality mark, but a more powerful laser can use 100 percent power at 30-50 percent speed to accomplish the same results. (Note: Personal experience has taught me that using more power than necessary to mark highly-reflective metals can damage the lens of higher power lasers. It’s best to test your settings on a piece of scrap metal to see how much power is actually needed to obtain a good mark and then limit yourself to using that amount.)

Barcodes come in a wide variety of styles and shapes, with each having specific applications. One of the most common examples of a barcode is on the front of your mail. This Data Matrix contains all the data the Post Office needs to deliver your mail. To locate the barcode tools, click on “Edit” and then “Insert Barcode…”.

     If you use the right speed and power setting then good-quality text as small as 4-6 points can be achieved using this process. In addition, lines as small as 2 points and intricate logos can also be produced, although holding small lines and accurate spacing for barcodes and 2D Matrix codes can be a challenge. If you do this type of work then you should always check your work with the appropriate reading device to ensure accuracy.
     In this example, let’s say we have a company logo, some text, some rule lines and a barcode that we need to engrave on a sample piece of metal that’s 4" x 6" and 3/16" thick. Once we create the layout in CorelDraw we can load the piece of steel into the laser and focus it. Once the job is loaded, we can select the power settings. In this case, we are using a 50 watt laser so we will engrave at 100 percent power and 30 percent speed. There is no advantage to using air assist with laser fusible coatings.
     Once we have marked the piece of metal, the surrounding chemical can be removed with water. Allow the engraved plate to soak in water for a few minutes and then rinse it with tap water and dry it lightly with paper towel to remove water spots. The final results should be a dark black mark that is permanent enough that the only way to remove it is to grind it off. This process is so reliable that it’s used a great deal in the automotive and aircraft industries where the metal will be exposed to water, chemicals or corrosion.
     Since this particular layout contains a barcode, it would be wise to attempt to read the code to ensure readability and accuracy. If our sample reads well then it is safe to assume the copies that follow will also read well, but again it is always best to check them to be sure.

The popup menu for barcodes allows you to select the type of barcode and to enter the information the code is to carry. These screens allow you to customize the size of the code, resolution, type fonts used and other data to make your barcode fit your specifications. Once you have worked your way through the three pages of barcode choices, the software will place the finished barcode on your working page. It can then be moved, altered or duplicated as needed just like any other piece of digital art.

     When using a laser fusible coating with metals other than steel, stainless steel, pewter or chrome, the results can vary so always test the metal before you attempt to engrave an actual product from a customer. Some brass will accept the chemical mark while other brass alloys will not. In addition, metals that have any kind of coating (such as lacquer) typically will not perform well.
     The market for engraving uncoated metal can be very widespread, from something as simple as stainless steel pet tags to something extremely complex like aviation control panels. I have used this process to produce a variety of control panels as well as measuring devices for railroad cars, maintenance panels for natural gas valves, safety markers for chemical plants, signs for ships, pet tags and data plates for electric motors.
     The quality of the mark which can be produced is excellent and the profit margin can be excellent as well. Where I’m located, engravers charge about $1 per letter to rotary engrave stainless steel without color filling. By using this process, I can beat that price by a mile and produce a better product that is a dense black, making it easier to read, and which will last indefinitely.
     On a final note, beyond the warnings for using the proper ventilation any time you are working with a laser, my strongest warning for using laser fusible coatings involves the use of aerosol cans. After use, be sure to turn the can upside down and spray into a trash can or some other receptacle until the nozzle is clear of the chemical. This chemical is notorious for clogging nozzles and once clogged they can’t be cleaned. Some distributors sell replacement nozzles just for this reason.
Engraving Barcodes
     Barcodes come in a wide variety. Many are identified by numbers such as a Code 39 or Code 128; there are UPC codes like the ones used by retailers and codes used specifically by UPS or the Postal Service and many more. Add to this mix those being used by the Department of Defense called 2D Matrix codes and it becomes a dizzying array.

Enlargement of a barcode.   BarTender™ is one of the most common and popular software packages for creating barcodes.

     You may be surprised at how many different types of businesses use barcodes these days, usually as a “key” code. This is when a barcode reader is connected to a computer that compares the number indicated by the barcode to an object, product, document, address, etc. in a database in the host computer. Most barcodes are pretty much worthless without a reader connected to the host computer. However, that is not the case with a few codes such as the 2D Matrix which can actually contain quite a large amount of information within itself.
     While 2D Matrix codes still require a special reader to interpret the code, these checkerboard-like codes do not always require a host computer since they can contain both numbers and the alphabet. They can also be grouped into clusters to double, triple or quadruple the amount of information contained in each Matrix. One of the more common uses for these is with your mail. If you look closely you’ll notice that most pieces of mail these days have a 2D Matrix next to the cancellation mark.
     The more common codes can be generated in a number of ways. The later CorelDRAW versions contain the ability to create some of the most common barcodes. If you are working with some of the more elaborate codes or do a lot of jobs that require special codes, including sequential serial number barcodes, the best approach is probably to invest in one of the many barcode software programs available such as BarTender. There are also a lot of Freeware and Shareware programs available on the Internet.
     Laser engraved barcodes work on just about any material that offers contrast in the mark, but the easiest materials I have found are flat black anodized aluminum or a special material made just for barcoding by Horizons called Labelsheets, which is part of their AlumaMark line. This is a die-cut, nonreflective, self-adhesive material that lasers with very high resolution to ensure easy readability. Labelsheets is available directly from Horizons or by special order from engraving material distributors such as Johnson Plastics. Black anodized aluminum is available from most metal or engraving suppliers and comes in 12" x 24" sheets.


Opening the Jigsaw Puzzle Creator opens this screen that allows you to choose how complex you want to make the puzzle. Close-up of printed puzzle after Jigsaw Puzzle Creator has added cut lines. Before sending the puzzle layout to the printer, it is necessary to remove the cut lines temporarily so they don’t show up on the actual printout. To do this, click on the transparency square in the color chart at the upper right of the color pallet.

     Barcodes and even 2D Matrix codes can be engraved onto a host of other materials as well. Although some care must be taken to ensure there’s enough contrast for the barcode reader to be able to read the code easily, almost any material that provides a reasonable amount of contrast will work. These materials include engraving plastics of all kinds, laser engravable foil products, coated metals and, as demonstrated earlier, metals that are receptive to laser fusible
coatings.
     As far as tips and tricks are concerned, the secret to doing barcodes is to use the right amount of power for the material you’re using. If you use too much power, especially with the laser-markable aluminum materials, then you risk causing the lines or dots to flair out. Excessive power will widen and distort the lines and reduce the built-in spacing between the bars.
     On the other hand, if you use too little power then you run the risk of not creating a solid, distinct mark, which also makes it difficult for the barcode reader to do its job. When creating barcodes, the goal is to produce clear, crisp images with solid straight lines and good contrast and with line widths that exactly match the size and proportion of the original barcode image.
     If you’re using CorelDRAW’s built-in barcode feature, all you need to do to get started is open a blank page, click Edit and then select the Insert Barcode option. On the first screen, select the type of barcode you desire and type in the data you want the barcode to represent. Some types of codes accept only numbers while others accept both numeric and alpha characters. There are two additional pages of choices about the barcode you are creating. In most cases, you can just click through these. On the fourth page of the barcode pop-up menu, click “Finish” to see the barcode created on your page in CorelDRAW.
     Barcodes are now a fact of life and are being used everywhere. For at least a half century our industry has produced millions of little nameplates and ID tags, with an emphasis on lettering and numbering. Thanks to our modern lasers, we can also now offer our customers tags and plates containing “indestructible” machine-readable barcodes and data matrices. Along with that comes a myriad of new customers and, hence, new profit opportunities.
Jigsaw Puzzles
     Jigsaw puzzles aren’t just for kids anymore. Serious business people and organization managers are using them as ad specialties or part of their marketing programs. Custom puzzles also make nice gifts for kids of all ages– especially for those recipients who already have everything.
     Creating jigsaw puzzles with a laser engraving system is not something many retailers offer their customers. That might change, however, once laser owners realize how fun and profitable these products can be, especially with all of the interesting marketing possibilities that exist.
     Making puzzles with a laser can be done using a variety of materials including thin sheets of wood or stiff sheets of cardboard called tagboard. Wood is considered especially valuable and unique for such projects and it’s surprisingly easy to work with. A number of companies offer sheets of finished wood suitable for making jigsaw puzzles. If you have a 25-35 watt laser, the easiest type of wood to work with is 1/8" thick wood available in alder, walnut, cherry or maple. Alder wood is especially nice because it engraves with a lot of contrast.

This image is ready to send to the laser for cutting. Note the outer line will create the outside dimension of the puzzle while the red lines will form the individual puzzle pieces. Close-up of a wood puzzle layout after Jigsaw Puzzle Creator has added cut lines. When making a wood puzzle, laser the image first as shown here. This allows for a second pass if needed to darken the image. Once you are happy with the results, add the cut lines and run the laser again for vector cutting.

     For best results when creating these products, you want your laser to cut through the wood in a single pass with a minimal amount of heat so as not to damage the surface of the wood. As mentioned, other materials can also be used to make jigsaw puzzles such as heavy cardboard sometimes called tagboard. This is a laminated cardboard available in a number of thicknesses and is available from paper companies (that sell paper to printers), framers’ supply houses and some artist supply stores.
     In the example we’ll discuss here, I used a tagboard that was .05" thick with a white surface. Depending on the type of paper you use to print your image, the white surface can help keep the image bright. Because you will want to print something on the surface, you will need to print your image on some type of photo-quality paper and adhere it to the tagboard before cutting it on the laser.
     The actual making of a jigsaw puzzle is much easier than you might think. The easiest way to make a puzzle is to invest in the right software. In this case, I chose to use a program made for CorelDRAW called Jigsaw Puzzle Creator for CorelDRAW. This program generates the vector cutting layout that cuts all of the interlocking puzzle pieces and is available from www.oberonplace.com for $39.99. The company offers a seven-day free trial so you can try it before you buy. When the program is loaded, it adds two icons on the Corel workspace.
     Once the program is loaded on your computer, simply import whatever photo, image or artwork you want to use. After sizing it to the desired size, click on the Jigsaw Creator icon and select how many pieces you want the puzzle to consist of and then click “Create.”
     If you’re printing a color photograph on tagboard, you have just one step to do before sending the photo to the printer. On the right-hand side of the screen, select the transparency square in your color bar. This will prevent the printer from printing the cutout lines that will still remain visible on the screen.
     You’ll want to use a fairly heavy weight photo-quality paper to print your color photograph on and then adhere it to the tagboard. I’ve found that the best way to do this is to dry mount it. Dry mounting can be done by most framing shops or, if you have a heat press, you can do it in-house. Unfortunately, dry transfer tissue costs about $100 per roll and although a roll might last you a lifetime, it’s a considerable investment if you’re only creating puzzles on an occasional basis. The other alternative is to partner with a frame shop or purchase a piece of a roll from a framer. There are other ways to mount the photograph, including spray adhesive and wall paper paste. The important requirement is to be sure you have excellent adhesion between the two materials since any air bubbles can result in a “flame-up” on the laser and a damaged surface.
  Here you can see the wood puzzle after it has been cut. The only remaining step is to package the puzzle for the customer.  

     When engraving either a wood or paper puzzle, position the artwork on the page (your laser work area) so it matches where you want the laser to cut out the finished product. I prefer to have the laser cut out the puzzle completely, including around the outside edges. Therefore, I position the artwork about 1/4" away from the rulers in the laser work area to keep the laser from burning the outside edges of the product when it cuts. Before sending the job to the laser, select the color you desire to represent cutting on your laser (any color can be used but I typically choose red).
     Now you can send the job to the laser. You may want to experiment with the power settings to get the best results with your particular laser. I use a 50 watt laser and it works well with a setting of 100% power and 20% speed for 1/8" wood. For heavy weight tagboard I use 60% power and 30% speed. It’s important to understand that all lasers can vary and may require slightly different settings to achieve the same results. Don’t be surprised if you have to run a few tests before you get it right.
     To prevent flame-ups, I’d suggest that you use your laser’s air assist feature as well as a vector cutting grid for these projects. As mentioned, getting the laser to cut completely through the material is vital. Again, all lasers will differ in the appropriate settings. In the examples I’ve shown here I used the following settings:


Paper Puzzle:
25 watt laser:
80% Power and 8% Speed, 150 ppi
50 watt laser:
50% Power and 8% Speed, 150 ppi
Wood Puzzle:
25 watt laser:
Raster: 100% Power and
70% Speed, 500 ppi

Vector: 80% Power and
5% Speed, 150 ppi

50 watt laser:
Raster: 100% Power and
70% Speed, 300 ppi

Vector: 50% Power and
10% Speed, 150 ppi

     Once the laser has done its job, remove the entire cutting grid with the puzzle setting on it. Now, slide the puzzle off the cutting grid and onto another sheet of tagboard while still assembled. At this point, the puzzle can be cleaned and packaged right on the tagboard or broken apart and boxed. Wood puzzles can be cleaned with rubbing alcohol. Paper puzzles require more care when cutting so cleaning is not necessary.
     Idea: If you have sublimation capability, a great way to print color images is to sublimate them onto Rowmark Mates, a self-adhesive film, and place that on tag-board or wood. The surface of the Mates product is very durable and the adhesive bonds very well. Be sure to work out all air bubbles as quickly as possible after applying the Mates material to the tagboard or wood substrate.
     As mentioned earlier, jigsaw puzzles are not just for kids. A lot of people order them as gifts, mementos, ad specialties, etc. People really like puzzles containing pictures of their kids, their cars, their boats—just about anything they have an emotional attachment to. And they’re a lot of fun to create, not to mention profitable!
Conclusion
     I realize we’ve covered a lot of information in this article, but this is just a taste of what we have in store for readers in this article series. There will be many more laser engraving applications to consider in future installments of this series, including things like multi-tile murals, ADA signage with Braille, rubber stamps, embossing seals and dies, stencils, vector cutting and more!


    

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